product description  This product is an Ewelink relay. The 2CH/4CH WiFi smart switch (dry contact) does not require rewiring, and the traditional switch can be easily upgraded. Support: mobile phone control, voice control, manual control, timing control, sharing control, camera binding, status feedback, jog/self-locking/interlocking mode Intelligent voice control: Goodle Home, IFTTT, Nest, amazon echo, Mi Home, Xiaodu, Tmall Genie, Ezviz, DingDong. Customized exclusive timetable: two timing modes (1: delayed task. 2: timed task.) 8 hours smart timing Bound camera: EWelink loT camera Equipment sharing: 1: One mobile phone can control multiple relays (the number of controls is not limited), 2: the customer's multiple mobile phones control the same relay (the number of mobile phones is not limited). Power-on response: custom power-on status, each channel can be individually customized power-on status, with its own shutdown memory (default shutdown), no need to worry about the safety hazards caused by sudden power failure Three modes: 1: Self-locking mode: all four devices are independently controlled and do not affect each other 2: Interlock mode: (Only one of four devices can be opened at the same time) When one device is turned on, the other devices are automatically turned off at the same time. 3: Jog mode; (the jog duration can be set by yourself) When the device is turned on, it will be automatically closed after 0.5~3600 seconds. Status feedback: When the device is triggered, the action and time of the device operation. It can be viewed in the operation object APP, which is clear at a glance.  Mode conversion tutorial video